Tasnim � Spokesman for the Atomic Energy Organization of Iran (AEOI) said Tehran has not backed off from pursuing a complaint about the US move to extend Iran Sanctions Act (ISA), saying its implementation will be a flagrant violation of the Joint Comprehensive Plan of Action (JCPOA).

In an interview with IRINN on Saturday, Behrouz Kamalvandi said Iran has not dropped its compliant about the US breach of the JCPOA by extending ISA.

�We are still pursuing,� he noted, warning that Iran�s �serious reaction� will be shown after implementation of ISA.

Representatives from Iran, the Group 5+1 (Russia, China, the US, Britain, France and Germany) and the European Union gathered in Vienna on January 10 to address Iran�s complaint about extension of ISA.

In December 2016, the US Senate voted 99-0 to extend the ISA for another decade. The bill was passed by the House of Representatives nearly unanimously in November. The renewal of ISA took effect on December 15 with a procedural protest from President Barack Obama, who decided to let the legislation become law without his signature.

Nonetheless, the recent session of the JCPOA joint commission - a group tasked with monitoring commitments to the nuclear deal� ended with a press release that just �recognizes the US assurance� that ISA extension would not violate the nuclear accord.

Iranian President Hassan Rouhani had already warned that implementation of ISA will constitute a �clear and flagrant violation of the JCPOA� and draw a �very harsh reaction� from Tehran.